SmartAlarm+3 vs BT21
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SmartAlarm+3
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Stay in control of your security system wherever you are. The Banham SmartAlarm+3 enables you to easily manage your burglar alarm remotely and get real-time alerts and updates. Features include: - Arm & Disarm your intruder alarm system from anywhere - See at a glance what’s set and not set so you can easily check and amend your level of security based on who is in the property - Geo location feature reminds you to set your security system when you leave your property - Get real-time alarm alerts - Get notifications whenever the alarm system is armed or disarmed. - View your history so you can see a full list of what’s happened with your alarm system - Alert feature enables you to send your location details to named contacts at once - Create ‘bubbles’ of contacts and see who’s bubble you’re in, so you can get location updates - Set shortcuts for common tasks, such as a full or partial set of the alarm without even needing to open the app - Choose which notifications you’d like to receive - Call our 24/7 alarm support team directly from within the app Important note: this app will only be activated upon purchase and after installation by a Banham engineer. If you have CCTV and entry systems you will need to use the Banham SmartAlarm+2 app.
BT21
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Customise your 7 day heating schedule faster than ever before with the BT21 app. Connect via bluetooth and control all of your thermostat settings quickly and easily. Once you've set up one thermostat, copy and paste all of your settings to another thermostat with easy presets. - Quick and easy heating schedule. - Copy presets to multiple thermostats. - View temperature data for the last 7 hours. - View %heating time for the last 7 days. - Send remote technical reports. - Manage temperature limits and calibration. - Set and manage all thermostat settings. - Connect to a wireless sensor (sold separately). - Lockdown mode to prevent tampering. - Hide unwanted thermostats. - Switch between heating, snow melting and power limit modes. - Switch between air, floor and remote sensors. - Access to online user guides and videos.
Screenshots
Verdict
The clearest difference is update cadence: SmartAlarm+3 at every 4 months against BT21's every 10 months. BT21's advantage is iOS requirement (12.4 vs 15.6). On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
SmartAlarm+3 ships an update every 4 months, BT21 every 10 months. The most recent releases landed on October 25, 2026 and September 29, 2026 respectively.
| Parameter | SmartAlarm+3 | BT21 |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 4 months — better | Every 10 months |
| Ads | No | No |
| In-app purchases | No | No |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 15.6 | 12.4 — better |
| Further details — not scored | ||
| Size | 307 MB | 23 MB |
| Age rating | 4+ | 4+ |
| Developer | Pyronix Ltd. | Thermogroup UK |
In-app purchases
SmartAlarm+3
No in-app purchases
BT21
No in-app purchases
Questions
Is SmartAlarm+3 free?
Is BT21 free?
Do SmartAlarm+3 or BT21 have ads?
Which is updated more often, SmartAlarm+3 or BT21?
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